THE SGI SCREAM-SAVER

Chemistry Department, Indiana University, Fall 1996

This newsletter is available at the begining of each month and covers the chemistry SGI cluster and the software available on it. If you want to subscribe, please contact Marty Pagel or Katherine Mann (MSC, A421)

Items Covered in this Edition:


Research Group System Administrator meeting

All Research Group System Administrators are strongly encouraged to attend the Research Group System Administrator meeting on Thursday, Nov 14, at 2:30 pm in Room A400. Topics will include: This is also a good time for Research Group System Administrators to bring questions and suggestions about SGI workstations in research labs.

IMPORTANT NOTE: Two research SGIs have had recent hardware failures and one other workstation had some files accidentally deleted. None of these machines had a current backup. The Research Group System Administrator is responsible for backups of the workstation in his/her research lab.


C687: Computer Methods in Biochemistry

This 3 credit hour biochemistry course will be taught by Prof. Martin Stone during the Spring 97 semester. This course will cover a variety of computer methods relevant to studying biomolecular structures. The emphasis will be on hands- on experience and practical skills using Silicon Graphics workstations. Examples of topics to be covered are: This class will benefit students who work on aspects of protein or nucleic acid structure-function relationships, structure determination, and design of ligands for these biomolecules. Enrollment is limited due to the limited computer resources. Biochemistry majors and those working directly with biomolecules will be given preference. Students interested in this class should contact
Prof. Stone.

New Stuff!

The MolViz Staff is currently converting the hardcopy SGI Users Guide to web pages available at the
MolViz web site. Additional notes are available at this MolViz site that are not available in the hardcopy guides. For example, notes about using PCMODEL and Mopac to calculate structures and transition states are now available.

AutoDock is installed on several SGI workstations in the Department. The output of this program is a series of ligand structures that are "docked" in the binding pocket of a macromolecule. This is accomplished by performing a Monte Carlo simulation of a flexible ligand as it randomly fluctuates about a static macromolecule (the macromolecule is represented by a large 3D grid). This differs from "traditional" docking methods, where the user had to direct the ligand into the binding pocket. While this program is CPU-intensive, preliminary results in the MolViz Facility have shown it to be very informative. Several small "interface" programs have been written by the MolViz Facility staff to transfer structures between InsightII and AutoDock. MolViz AutoDock notes are also available.

A new CSD upgrade is being installed at UCS; our local CSD software will be upgraded soon after UCS returns this software to us. InsightII version 4.0.0 just arrived and will be installed soon. PCMODEL for all versions of the IRIX operating systems has been installed. A version of GMMX for all IRIXs will also be installed soon. Netscape version 3.0 is now available for SGI workstations, although the latest version of Netscape that is officially recommended by SGI is version 2.02S. If you need an updated version of Netscape, contact the MolViz Facility Staff.


Retired Software

The following software has become obsolete due to the popularity and features of Netscape. This software will no longer be supported by the MolViz Staff: If one or more of these capabilities is needed but it is missing from Netscape as configured in your account or on your workstation, contact the MolViz Staff. These applications will soon be removed from all departmental SGIs; research SGIs that use copies of these programs on the departmental servers will also lose access to these programs. The MolViz Facility Staff recommends that you remove copies of these programs that reside on your local machine.

The StereoView Classroom

The
StereoView Classroom (room A400) is a fully operational projection system for SGI and PC (Windows 95), and VCR output. Output from a Macintosh can also be arranged if you supply the computer. "Stereo-Ready" outputs can also be displayed in active 3D mode with CrystalEyes LCD glasses. The newest feature of A400 is the ability to capture video & audio from the SGI onto a VCR tape or transfer VCR tape or IU cable TV output to the SGI. Contact Bob Addleman or Katherine Mann to schedule this resource.

While this classroom is operational, the MolViz Facility staff needs your suggestions and comments to make this resource fully compatible with your research and instructional needs. If you would like to comment upon the functionality of this resource, please contact the MolViz Facility staff.


Upgrade to IRIX 6.2

IRIX 6.2 has been installed on pchem01, pchem06, stereo1, and selected research SGI workstations. It is available for installation on SGI workstations that have a CPU labeled "R4000" or higher (type hinv to list your CPU type). Most Indigo workstations have R3000 CPUs and cannot be upgraded. While there are no immediate and specific reasons to upgrade your operating system, the MolViz Facility Staff recommends upgrading to IRIX 6.2 to stay concurrent with new state-of- the-art features offered by SGI and other software vendors. IRIX 6.2 also requires less disk space than previous operating systems.

Automounting Disks between SGI workstations

File systems (selected directories and files on a hard disk drive) on one SGI workstation can be shared, or "mounted", by other SGI workstations. The standard mounting method keeps the files mounted all of the time. This requires a perfect network and significant efforts by system administrators to maintain and guarantee that files are always mounted. To make matters worse, rebooting your system while a remotely mounted drive is unavailable can cause your system to hang or run sluggishly while it tries to establish the connection.

We have now implemented "automount" on all of the Departmental SGIs and most of the Research Group SGIs. "Automounting" automatically mounts a remote file system only when a user executes an application requiring access to a file on the remote file system. When the application is finished, the system detects the inactivity and automatically unmounts the file system after a delay (currently 5 minutes). For example, users who have a home directory on a remote system can log onto an SGI workstation and their home directory will be automounted and immediately available. Automounting eliminates network traffic and system administration efforts when the SGI workstations are not being used, and it is a popular feature used in many SGI networks throughout the world.

Automounting causes several minor changes. Most importantly, the path name of home directories that exist on remote systems are prefaced with /ruser, and the path name of application directories that exist on remote systems are prefaced with /remote. For example, if Rachel has a home directory on CHEMVGX (/chemvgx/people/rachel) and she logs onto PCHEM01, her home directory on PCHEM01 is named /ruser/chemvgx/people/rachel. If Rachel starts InsightII (by typing InsightII) on PCHEM01, she accesses /remote/saturn3/model/biosym/950/bin/insightII, the copy of InsightII on our server SATURN.

Commands that access all file systems on the SGI workstation will access only file systems that are currently automounted. For example, df will only list file systems that have been used within 5 minutes. Since most people use these commands to access only file systems on which they are currently working (and are therefore automounted), this should not cause problems.

The privilege to mount a remote file system is no different than with the previous hard mounting and is defined in the /etc/exports file of the system on which the remote file system is physically installed. The remote file systems that can be automounted onto the local workstation are listed in /etc/auto.ruser and /etc/auto.remote.

Maintaining links to remote file systems such that specifying /model has teh same effect as /remote/model, for example, defeats the purpose of automounting and effectively re-establishes the hard mounts as they wre before. It is recommended that any such links be removed and appropriate changes be made in any scripts (/etc/cshrc, /etc/cshrc.local, etc.), support files (/etc/passwd, etc.), or other programs affected. Failure to follow this precaution could result in your system becoming unstable, very sluggish, or even unbootable when a remote file system is down and you have links to this file system.


New Workstations offered by Silicon Graphics, Inc.

The Indigo, Indy, Indigo2, and Challenge workstations have been replaced by new types of workstations:
Desktop workatations
The desktop O2 workstation includes a 180 MHz R5000SC CPU, 64 MByes of memory and 2.2 GBytes of disk space, all for $6558 (academic price). This type of workstation, with the same configuration, used to cost approximately $16,000 just 6 months ago.
Server workatations
The server Origin workstation includes 1 to 128 R10000 CPU, 128 MB to several GBytes of memory, and 2.2 to 9.1 GBytes of disk space. Prices start at approximately $14,897. The same type of workstation used to cost approximately $35,000 just 6 months ago. The Origin is built in a very modular way (in fact, the code name of this product during development was "LEGGO"). Additional CPUs, RAM, and disks can be added when your needs (and budget) grow.
Why are these machines so inexpensive? There are several reasons, but the biggest reason is due to VOLUME production of the processor chips. Since May 1996, both Nintendo and Sony have ordered over 12 million RISC- based MIPS CPU chips to be used in their consumer game products. Production costs have decreased from $2000 to $30 per chip!

If you are interested in purchasing a new SGI workstation, please contact Marty Pagel . Volume discounts and/or trade-ins of existing SGI workstations can often be arranged.


Back to Scream Saver Index
Return to MolViz Home
Send comments to chemvis@indiana.edu
Last updated: 01/23/2001